X-ray imaging is widely used in various fields of life. For example, X-ray imaging has been a standard medical diagnostic tool for decades.
A typical X-ray image acquisition apparatus suitable for low energy X-rays includes a phosphor X-ray conversion screen and a photo detector array aligned with each other. The phosphor conversion screen generates optical light photons in response to the X-ray radiation. The optical light photons are transmitted to the photo detector array under the conversion screen. The photo detector array generates electric signals in response to the optical light photons. Electronics circuitry coupled to the photo detector array processes the electric signals and generates images.
A typical high energy X-ray image acquisition apparatus includes a copper screen and a Gadolinium Oxysulfide panel over a photo detector array. The high energy X-ray radiation passes through the copper screen, which absorbs a portion of the X-ray radiation and generates energetic electrons. The electrons pass into the Gadolinium Oxysulfide panel and generate optical light photons. Another portion of the X-ray radiation passes through the copper screen and interacts with Gadolinium Oxysulfide to produce optical light photons. The photo detector array senses the optical light photons and generates electric signals in response thereto.
Depending on the particular medical procedure or application, X-ray radiation at different energy levels may be used. For example, in the field of medical diagnostic procedures, low energy “diagnostic” X-ray images are generally used in diagnostics, and high energy X-rays are generally used for treatment in radiation oncology. High energy X-rays may also be used for imaging that are produced in conjunction with the treatment for better patient alignment and target motion detection during the treatment. The quality of the acquired image depends on the image acquisition procedures and the equipment used.
X-ray images at different energy levels are presently created using different image acquisition apparatuses as described above. Maintaining multiple sets of X-ray image apparatuses may increase the operating and overhead costs for a medical diagnostic facility. It may also affect the efficiency of the facility by increasing the idle time of the apparatuses. These effects are exasperated further for those facilities having relatively small patient bases.
Accordingly, it would be advantageous to have an apparatus that is capable of forming images using X-rays at different energy levels. It would be desirable for the apparatus to be simple, reliable, and capable of being used with an existing X-ray imaging system. It would be of further advantage to be able to optimize the image quality for its intended use.